What is the brain fog that affects covid-19 patients?

(CNN Spanish) — Cognitive decline and covid-19 are closely related, recent research related to side effects of the pandemic has shown.

One of these symptoms is “brain fog,” as cognitive decline is known, which can persist for months in some covid-19 patients who were hospitalized, and even in some who were not, according to research published in 2021 in JAMA Network Open magazine.

In this study, it was established that around a quarter of the patients who had covid and who were part of the registry of the Mount Sinai Health System, in New York, experienced some memory problems. And while patients who were hospitalized were more likely to suffer from so-called “brain fog” after a coronavirus infection, some outpatients also suffered from cognitive decline.

“This pattern is consistent with early reports describing a dysexecutive syndrome after COVID-19 and has considerable implications for occupational, psychological, and functional outcomes,” the researchers wrote.

Other research, published in April 2021 in the journal Lancet Psychiatry, found that as many as 1 in 3 people with Covid-19 had longer-term mental health or neurological symptoms.

Among the most recurrent symptoms of brain fog “are trouble concentrating, and they often have more anxiety and depression,” Dr. Gabriel Erausquin, a professor of neurology at the University of Texas Health Science Center, told CNN. who did not participate in this study, but did participate in another that studied cognitive impairment and symptoms of Alzheimer’s disease in patients with covid-19.

Covid-19: a list that shakes 4:23

Covid causes long-term memory problems

That other study in mention of the Center for Health Sciences of the University of Texas was done in the Argentine population and showed the relationships between covid-19, cognitive deterioration and the acceleration of symptoms similar to those of Alzheimer’s. It was published in July 2021.

Researchers from an international consortium sought to understand the long-term consequences of covid-19 on the central nervous system. They found memory problems and biological markers similar to those seen in Alzheimer’s patients. Both diseases are characterized by inflammation of the brain.

Three to six months after infection, more than half of the patients still had problems with forgetfulness and about a quarter had additional cognitive problems. The degree of illness of a patient with covid-19 was not an indicator of whether she would experience cognitive decline.

“The severity of the initial illness does not predict who is going to get this,” “In fact, many of them had minimal symptoms: just a cold or loss of smell.”

Eruasquin and his colleagues studied more than 200 adults aged 60 and over from Argentina who had been infected with covid-19.

Covid-19: a list that shakes 4:23

Cognitive problems of covid-19

Among the cognitive problems presented by these patients were:

  • persistent forgetfulness
  • Difficulty sequencing tasks
  • forget words and phrases

“These findings suggest that patients who have had COVID-19 may have an acceleration of Alzheimer’s-related symptoms and pathology,” Dr. Thomas Wisniewski, professor of neurology at New York University Grossman School of Medicine, who participated in this study.

According to the CDC, other long-term symptoms of covid are:

  • Tiredness or fatigue that interferes with daily life
  • Symptoms that worsen after physical or mental exertion
  • Fever
  • Difficulty thinking or concentrating (called “brain fog”)
  • Headache
  • sleeping problems
  • Dizziness when standing up (lightheadedness)
  • Feelings of pins and needles
  • Change in smell or taste
  • depression or anxiety

brain changes

In addition to cognition problems, people who have had mild cases of covid-19 may have accelerated brain aging and other brain changes, according to a study published in the journal Nature in March 2022.

The study found that the brains of those with COVID-19 had greater gray matter loss and brain tissue abnormalities compared to those without COVID-19. Many of those changes were in the area of ​​the brain related to the sense of smell.

“We were very surprised to see clear differences in the brain even with mild infection,” lead author Gwenaëlle Douaud, an associate professor of neuroscience at the University of Oxford, told CNN in an email.

Douaud and colleagues evaluated brain images of 401 people who had COVID-19 between March 2020 and April 2021, both before infection and an average of four and a half months after infection. They compared the results with brain imaging of 384 uninfected people of similar age, socioeconomic status, and risk factors such as blood pressure and obesity. Of the 401 people infected, 15 had been hospitalized.

Douaud explained that it’s normal for people to lose 0.2% to 0.3% of gray matter each year in areas of the brain related to memory as they age, but in the study’s assessment, people who who had been infected with the coronavirus lost an additional 0.2% to 2% of tissue compared to those who had not been infected.

— With reporting by CNN’s Jacqueline Howard, Lauren Mascarenhas and Nadia Kounang